The inventive concept relates generally to memory technologies. More particularly, certain embodiments of the inventive concept relate to memory systems and methods in which segment cleaning is performed in the context of a log-structured file system.
A log-structured file system is commonly used in server storage systems comprising hard disk drives (HDDs). Because HDDs use a rotary motor, they have seek latency and rotational latency. Therefore, the log-structured file system may configure an entire disk as one log and perform sequential write operations only. For instance, when modifying a file, the log-structured file system may not modify data at an original position. Instead, it may add modified data at the end of the one log, so the log is continuously extended in one direction.
Where a log cannot be extended any further, segment cleaning may be performed to return invalid data in the log to a free area in which data can be stored. The invalid data is data that is no longer valid because it has been deleted or updated. The segment cleaning requires frequent read operations on victim segments that should be moved. These frequent read operations, however, increase system overhead.